Apparatus, and associated method, for paging an access terminal in a radio communication system

ABSTRACT

Apparatus, and an associated method for facilitating paging of an access terminal operable in a radio communication system. A plurality of random numbers are generated. And, for each of the random numbers, a hash value is created by applying the random number to a hash function. The hash values identify bit locations of a paging message. When the paging message is formed, bit locations associated with the hash values are populated with bit values that identify whether the access terminal is being paged. And, the access terminal checks the bit values at the bit locations associated with the hash values to determine whether the access terminal is being paged.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention claims the priority of provisional patentapplication No. 60/825,197, filed on Sep. 11, 2006, the contents ofwhich are incorporated herein by reference.

The present invention relates generally to a manner by which to page anaccess terminal of a radio communication system to alert the accessterminal of a pending call, or other communication. More particularly,the present invention relates to an apparatus, and an associated method,that provides for the generation, sending, and analysis of a quick pagemessage upon a paging channel, such as a QPCH (quick paging channel)defined in an exemplary cellular communication system. The page messageis formed in a manner that reduces the likelihood of occurrence of falsewakeup of an access terminal. Excessive battery depletion, as a resultof false wakeup of the access terminal, is avoided.

BACKGROUND OF THE INVENTION

Advancements in communication technologies have permitted thedevelopment and deployment of new types of communication systems andcommunication services. Cellular telephony, and associated communicationservices available therethrough, are popularly utilized by many,typically providing users with communication mobility and also providingthe capability of communications when the use of wireline communicationsystems would not be practical or possible.

While early-generation, cellular communication systems providedprimarily for voice communications and only limited data communicationservices, newer-generation systems increasingly provide for high-speeddata communication services at variable data communication rates. ACDMA2000, cellular communication system that provides for EV-DO servicesis an exemplary type of new-generation, cellular communication systemthat provides for high-speed data services. Operational details andprotocols defining communications and operational requirements ofdevices of the system are set forth in an operating standardspecification. Various aspects of operation of the CDMA2000 EV-DOcommunication scheme remain to be standardized and certain parts of theexisting standard specification are considered for amendment. Varioussuccessor-generation communication schemes are also undergoingstandardization and yet others are envisioned to be standardized.

For instance, a revision to the standard specification, release B of theCDMA2000 EV-DO specification standard defines a quick paging channel(QPCH) available upon which to broadcast access-terminal pages by anaccess network (AN) to an access terminal (AT). The QPCH was adopted inindustry contributions 3GPP2 C20-20060323-013R1 and 3GPP2C20-20060323-003R1 and published in 3GPP2 document C.S0024-B V1.0.Generally, pages are broadcast by the access network to an accessterminal to alert the access terminal of a pending communication. And byso alerting the access terminal, the access terminal performs actions topermit the effectuation of the communication. Page indications broadcastupon the quick paging channel are broadcast in a manner that facilitatesreduced battery consumption of the access terminal by reducing thebattery consumption of the battery of the access terminal. Increasedbattery longevity is provided, reducing the rate at which a battery ofthe access terminal must be recharged. The access terminal is, as aresult, able to be operated for a greater period of time betweenrechargings or battery replacement. The aforementioned promulgationsprovide for broadcast of a message including page indications upon aphysical logical layer that is monitored by the access terminal. Theaccess terminal monitors the QPCH prior to monitoring the controlchannel to receive regular, control channel MAC (medium access control)messages such as page messages. A quick page message is broadcast uponthe QPCH that contains quick page indicators. The quick page messageincludes a number of quick page indicator slots populated with quickpage indicators.

During operation, a mobile station hashes to a quick page indicatorlocation, i.e., slot, within the quick page message based upon a sessionseed, a 32-bit pseudorandom number. If the quick page indicator of thequick page indicator slot to which the access terminal hashes indicatesthat the access terminal is not being paged, the access terminal entersinto a sleep state, a reduced-power state, in which the access terminaldoes not remain powered at a level to receive the regular controlchannel MAC messages. Power savings is particularly significant in theevent that the control channel MAC messages are lengthy and spanmultiple control channel frames or capsules.

In the existing scheme, however, the access terminal is susceptible tothe occurrence of a false wakeup, that is, the access terminal does notenter into a sleep state but, rather, the access terminal enters into anactive state to monitor the regular control channel for reception ofregular control channel MAC messages even though there shall be nomessage for the access terminal. Because the communication system is amulti-user system, there is a possibility that another access terminalthat is being paged has its page indication hashed to the same pageindication slot. As the number of access terminals that are paged in asystem increases, the likelihood of occurrence of a false wakeupcorrespondingly increases.

If a manner could be provided by which to reduce the occurrence of falsewakeups, improved battery longevity of the access terminal would bepossible.

It is in light of this background information related to paging by anaccess network of an access terminal that the significant improvementsof the present invention have evolved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a functional block diagram of a radio communicationsystem in which an embodiment of the present invention is operable.

FIG. 2 illustrates a graphical representation of the relationshipbetween the probability of occurrence of a false wakeup as a function ofthe number of pages in a multi-user communication system for variousnumbers of hashes.

FIG. 3 illustrates an exemplary quick page message generated pursuant tooperation of an exemplary embodiment of the present invention.

FIG. 4 illustrates an exemplary quick page message generated pursuant tooperation of another exemplary embodiment of the present invention.

FIG. 5 illustrates formation of an exemplary quick page message pursuantto operation of another exemplary embodiment of the present invention.

FIG. 6 illustrates a method flow diagram representative of the method ofoperation of an embodiment of the present invention.

DETAILED DESCRIPTION

The present invention, accordingly, advantageously provides anapparatus, and an associated method, by which to page an access terminalof a radio communication system to alert the access terminal of apending call, or other communication.

Through operation of an embodiment of the present invention, a manner isprovided to generate, send, and analyze a quick page message, such as aquick page message generated and sent upon a QPCH (Quick Paging Channel)defined in a CDMA2000 EV-DO cellular communication system.

The page message is formed in a manner such that, when analyzed, theaccess terminal is less susceptible to occurrence of a false wakeup. Byreducing the likelihood of occurrence of false wakeup, excessive batterydepletion that occurs as a result of false wakeup is less likely tooccur.

In one aspect of the present invention, hashing is performed at both anaccess network and at an access terminal using the same input number,such as a session seed defined in the CDMA2000 EV-DO operatingspecification standard or other pseudorandom number, or another inputnumber, such as an access terminal identifier (ATI). Hashing isperformed upon the input number in the same manner, independently, atthe access network and at the access terminal. Multiple hashes areformed by hashing the input number in different manners, e.g., such asby rotating the bit sequence of the input number to create differenthash values. Alternately, different hash functions are used to createthe different hashes. Formation of the multiple hashes is sometimesreferred to herein as multi-hashing. Each hash function operation iscarried out in the same manner at the access network and at the accessterminal so that the resultant hash values generated at the respectiveentities are identical. For instance, hashing is first performed at boththe access network and at the access terminal upon the input number innon-rotated form. Then, the hashing is performed, again at both theaccess network and at the access terminal, upon the input number whosebits are rotated by a first number of bits. If additional hashing isperformed, the access network and the access terminal both perform thehashing upon the input number, whose bits are further rotated, again inthe same manner at the access network and at the access terminal. Bitrotation also decorrelates the hashed values.

In a further aspect of the present invention, the hashing is performedupon the input number by operation of a hash function, or algorithm,upon the input number. The hash function, e.g., is time-varying orotherwise, in some manner, generates hash values that aretime-dependent. And, if desired, if multiple hash values are generated,the hash values are further caused to be dissimilar. That is to say,when multiple hash values are generated, a later-generated hash value iscaused to be of a value different than any earlier-generated hash value.

In another aspect of the present invention, the access networkidentifies the number of hashes and the number of page indications thatare to be included in a quick page message to page a particular accessterminal. A signaling message is generated that includes an indicationof the number of hashes or page indications that are going to bebroadcast by the access network to a particular access terminal within apaging message. The access terminal, from this signaling message,ascertains the number of page indications that are going to be directedto the access terminal in the quick page message. Responsive to thisreceived number, the access terminal performs hashing upon an inputnumber to form an appropriate number of hash values, and such hashvalues are used pursuant to analysis of the page message, when received,to identify where in the page message to detect values of pageindicators.

In another aspect of the present invention, the number of hashesperformed by the access network and, correspondingly, the number ofhashes performed at the access terminal, is a selectable number. Thenumber is selected, at least in part, based upon the number of pagesthat are to be made to other access terminals. And, more generally, thenumber of hashes is responsive to communication activity in thecommunication system. When many access terminals are paged, the numberof page indications, and hash values, per access terminal is, e.g., asmall value. And, conversely, when only a small number of accessterminals are to be paged, the number of page indications, and hashvalues, is, e.g., large. Generally, the number of hash values andresultant page indications per access terminal, populated into a pagemessage for a particular access terminal, is inversely proportional tothe communication activity, that is, the number of other pages that aremade to other access terminals during a particular period of operationof the communication system. Ideally, the number of page indications andhash values per access terminal is chosen in a way to minimize theprobability of false wakeup.

In another aspect of the present invention, the hash values determinewhere in the page message that the page indications are populated. Thehashing performed at the access network and at the access terminal iscarried out in the same manners. The page indication locations of a pagemessage in which the page indication values are populated are the samehash values that are generated at the access terminal, and the accessterminal detects and analyzes the corresponding page indicationlocations of the page message, once received at the access terminal.

In another aspect of the present invention, in the event that any of thevalues of the page indications populating the page indication locationscorresponding to the hash values indicate that the access terminal isnot being paged, the access terminal enters into a sleep state. Forinstance, if the access terminal detects any page indication value towhich the access terminal hashes and determines the access terminal isnot being paged, the access terminal enters into a sleep state. Thereby,the access terminal is more quickly able to enter into a power-saving,sleep mode. Conversely, if the access terminal identifies a pageindication value populating a page indication location that indicatesthat the access terminal is being paged and the access terminal knowsthat multiple page indications are broadcast to the access terminal inthe quick page message, the access terminal monitors for the same pageindication value in another page indication location to which the accessterminal hashes. If the first positive indication is a false indication,monitoring of a second, or other, page indication locations prior todetermining finally that the access terminal is being paged reduces thelikelihood of occurrence of false wakeup. Thereby, the access terminaldoes not enter into an active state to receive a communicationresponsive to a false wakeup indication. Improved power consumptioncharacteristics of the access terminal result, providing better batterylongevity.

In another aspect of the present invention, a hash generator, and anassociated hash generation mechanism or hash generation algorithm isprovided. The hash values generated by the hash generator ensure, orsignificantly reduce the possibility, that the hash values, used to hashto locations in a page message for paging of different access terminals,shall be the same value. The occurrence of hash-value “collision” isthereby reduced or eliminated.

In these and other aspects, therefore, apparatus, and an associatedmethodology, is provided for an access network that selectably generatesa first page message on a first paging channel. A page indicationpopulator is configured to populate the first page with a selectednumber of page indications. A hasher is configured to generate aselected number of hash values. Each hash value is determinative ofwhere the page indicator populates the first page message with a pageindication. The hash values selected by the hasher reduce, or eliminate,the possibility of multiple populations of the same location of the pagemessage with multiple hash values.

In these and other aspects, therefore, further apparatus, and anassociated methodology, is provided for an access terminal thatselectably receives a first page message on a first paging channel. Ahasher is configured to generate a selected number of hash values. And,a page indication detector is configured to detect values of pageindications populating the first page message. Hash values that aregenerated are used to identify to the page indication detector where inthe first page message to detect the values of the page indications.

Referring first, therefore, to FIG. 1, a radio communication system,shown generally at 10, provides for communications with accessterminals, of which the access terminal 12 is exemplary. Thecommunication system forms a multi-user communication system thattypically includes a large number of access terminals and a plurality ofconcurrent communication dialogs. While only a single access terminal isshown in FIG. 1, additional access terminals, analogous to the accessterminal 12, typically form a portion of the communication system.

Communications are effectuated between an access terminal and a radionetwork 14, formed of fixed network infrastructure elements, such as abase transceiver station (BTS) 16 and a base station controller (BSC)18. The access network encompasses a geographical area within whichcommunications with the access network are possible. That is to say,when an access terminal is positioned within the area encompassed by theaccess network, the access terminal is generally able to communicatewith the access network, and the access network is typically able tocommunicate with the access terminal.

The communication system is operable in general conformity with theoperating protocols and parameters of an appropriate communicationspecification standard. The description set forth herein is exemplary,and the teachings of various embodiments of the present invention areimplementable in any of various types of communication systems.

As previously mentioned, the access terminal is alerted, by broadcast ofpage messages when a communication, initiated at the network, is to beterminated at the access terminal. A quick paging channel (QPCH), oranalogous channel, is defined. Quick page indications, populating aquick page message, are of values that identify whether an accessterminal is being paged. However, also as noted previously, particularlyduring times of heavy usage, a false wakeup of the access terminal mightoccur due to a quick page indication in the message intended for oneaccess terminal is broadcast within a slot that is also used by anotherof the access terminals. False wakeup prevents an access terminal fromentering into a power-saving sleep mode.

Accordingly, pursuant to an embodiment of the present invention, theaccess network includes apparatus 24, and the access terminal includesapparatus 26, that operate to reduce the likelihood of the occurrence offalse wakeup. The elements of the apparatus 24 and the apparatus 26 arefunctionally represented, implementable in any desired manner,including, for instance, by algorithms executable by processingcircuitry.

The elements forming the apparatus 24 are implemented at any appropriatelocation of the access network 14, including, as illustrated, at the BTS16 and BSC 18 or distributed amongst such entities as well as others.

Here, the apparatus 24 includes a quantity of hashes/page indicationsper access terminal determiner 32. The determiner is coupled to receive,as input indicia, indications of network activity on the line 34. Thenetwork activity is quantified, for instance, in a number of pagevalues. The network is aware, e.g., of the number of access terminalsthat shall be paged. Or, the number of page values comprises, e.g., anexpected number of pages, an average number of prior pages, or otherpaging quantity indicia. Responsive to the indication of the networkactivity, the determiner determines the number of hashes that are to begenerated and the number of page indications that are to be providedpursuant to paging of an access terminal in a quick paging message. Inan alternate implementation, the number of hash values is a set number,e.g., a fixed number greater than one. The fixed number of two, e.g.,appears to work well when the number of page indication locations in aquick page message is about one hundred eighty. The number of hashvalues and number of page indications correspond. An indication of thedetermined quantity is provided to a signaling message generator and toa hash generator, a “hasher”, 38.

A number known to both the access network and to the access terminal,such as a session seed or other pseudorandom number, or a number such asan access terminal identifier (ATI) is provided to the hash generator,here represented by way of the line 42. The hash generator hashes thenumber. That is to say, a hash function is performed upon the number togenerate a hash value. Different hash values are provided by, e.g.,rotating the number provided to the hash generator and performing thehash function, or algorithm, thereon. Multiple hash values aregenerated, for instance, by operating upon multiple rotations of thenumber. With an ideal hash function, all values are equally likely to begenerated. An exemplary hash function comprises a mathematical “modulo”operation. A time factor, known to both the access network and theaccess terminal, such as a system clock time, is, in one embodiment,further provided to, and used by, the hash generator in the formation ofhash values. Such factor is represented by line 43 in FIG. 1.

In a further embodiment of the present invention, the hash functionforms a hash mechanism that reduces, or eliminates, the possibility thatthe same hash value shall be selected as a result of multiple hashings.That is to say, in the further embodiment, unique numbers are generated,reducing the amount of “collisions” with, or of, access terminals thatare not being paged.

For example, the hash function comprises a so-called Algorithm S(selection sampling technique) taken from Knuth's “The Art of ComputerProgramming”, 3rd Edition, Chapter 3.4.2.

In another implementation, a generate Unique List PI Bits_A algorithm isused in which:

-   MBA=maximum number of bits available to be set-   nPI=number of PI bit locations to select-   iPI=number of PI bit locations found so far-   jPI=index running through iPI selections-   rnd=new random bit to be set. If this is the (jPI+1)st location we    need to add jPI to it, since jPI locations are already taken-   uListPI[1 . . . nPI]=sorted list of unique indexes of nPI bits to    select within MBA;

The algorithm is, e.g., comprises of this pseudo code:

generateUniqueListPIBits_A( MBA, nPI ) returning uListPI[ ] {   Verifyarguments and make sure enough bits are available to be set;   Select arandom across all bits and assign it to the first item in the   list,e.g.   uListPI[1] = random(1, MBA);   Now one by one select random bitsfrom remaining bits, e.g.   foreach ( iPI = 1→ nPI−1)   {     Let rnd =random(1, MBA − iPI), since iPI bits are not available     Insert thenew rnd location (from among available bits) to     uListPI, e.g.    foreach ( jPI = iPI → 1)     {       Shift indexes in uListPI toinsert rnd, so uListPI remains       sorted e.g.       if ((rnd + jPI) >uListPI [jPI]) found location so break       from loop;       elseuListPI [ jPI + 1] = uListPI [ jPI ];     }     uListPI [ jPI + 1 ] =rnd + jPI; Note jPI=0 if the loop exited     without break   }   ReturnuListPI[ ]; }

In another implementation, a generate Simple Almost Unique List PI BitsD algorithm is used in which:

-   MBA=maximum number of bits available to be set-   nPI=number of PI bit locations to select-   iPI=number of PI bit locations found so far-   jPI=index running through iPI selections-   rnd=new random bit to be set.-   auListPI[1 . . . nPI]=list of almost unique indexes of nPI bits to    select within MBA;

The algorithm is, e.g., comprised of this pseudo code:

generateSimpleAlmostUniqueListPIBits_D( MBA, nPI ) returning auListPI[ ]{   Verify arguments and make sure enough bits are available to be set;  Select a random across all bits and assign it to the first item in the  list, e.g.   auListPI [1] = random(1, MBA);   Now one by one selectrandom bits from remaining bits, e.g.   foreach ( iPI = 1→ nPI −1)   {    Let rnd = random(1, MBA − iPI), since iPI bits are not available    Increment rnd by 1 foreach smaller index found so far, e.g.    foreach ( jPI = 1 → iPI)     {       if ((rnd) > auListPI [jPI])rnd++;     }     auListPI [ iPI + 1 ] = rnd;   }   Return auListPI[ ]; }

In another implementation, a generate Simple Almost Unique List PI BitsK algorithm is used in which:

-   MBA=maximum number of bits available to be set-   nPI=number of PI bit locations to select-   jPT=index running through iPI selections-   rnd=new random bit to be set.-   auListPI[1 . . . nPI]=list of almost unique indexes of nPI bits to    select within MBA;-   vBitsSet[1 . . . MBA]=boolean local vector representing bits set so    far

The algorithm is, e.g., comprised of the pseudo code:

generateSimpleAlmostUniqueListPIBits_K(MBA, nPI ) returning auListPI[ ]{   Verify arguments and make sure enough bits are available to be set;  Set vBitsSet[ ] vector to false;   Now one by one select random bitschecking for single   collisions, e.g.   foreach ( jPI = 1→ nPI)   {    Select a new random number, e.g.     Let rnd = random(1, MBA);      Do a simple single rehash in case of collision, e.g.     if(vBitsSet[rnd]) rnd = ((rnd+MBA/nPI) mod MBA);     vBitsSet[rnd] = TRUE;    auListPI[jPI] = rnd;   } Return auListPI[ ];

The random number generation mentioned in the above, exemplary pseudocodes uses, e.g., existing methods with different keys and/or DECORRvalues.

The signaling message generator 36 to which the value determined by thedeterminer 32 is provided generates a signaling message, here generatedupon the line 45, that identifies the quantity determined by thedeterminer. The signaling message is broadcast to the access terminal12, thereby to alert the access terminal of the determined quantity. Thesignaling message generator may operate in conjunction with the QPCHgenerator and include the quantity in the QPCH message. The hash valuescreated by the hash generator 38 are provided to a page indicationpopulator 48. The page indication populator 48 is also provided with anetwork communication request, here provided by way of the line 52. Thepage indication populator selects page indication values depending uponwhether the access terminal is to be paged. For instance, when an accessterminal is to be paged, the page indication values are logical “1”values. In one implementation, all values are initially logical “0”values and then set as appropriate. The page indication values and theirassociated page indication locations, defined by the hash valuesgenerated by the hash generator 38, are provided to a QPCH, or other,message generator 54. The message generator forms a page message 56 thatincludes a plurality of page indication locations. The page indicationpopulator populates selected page indication locations of the messagewith the page indication values. The locations populated with a pageindication value are determined by the hash values generated by the hashgenerator 38. In like manner, page indications are formed for otheraccess terminals and hash values are generated to define at where in thepage message the page indications intended for other access terminalsare populated in the message generated by the message generator 54. Whenthe resultant message 56 is broadcast by the access network, accessterminals, such as the access terminal 12, are provided with anindication of whether the access terminal is to be paged.

Transceiver elements of the base transceiver station 16 cause broadcastof the messages generated by the message generator 54 of the apparatus24 upon a radio air interface, represented in FIG. 1 by the arrow 62.The message is delivered to the access terminal 12 as well as otheraccess terminals within reception range of the broadcast message. Theaccess terminal 12 includes transceiver circuitry, here represented by areceive part 64 and a transmit part 66. The receive part 64 operates toreceive signals sent thereto, such as the messages generated by theapparatus 24 of the access network. And, certain of the detected signalsare provided to the apparatus 26. Of significance here are detections ofthe signaling message generated by the signaling message generator ofthe access network and of the page message generated by the messagegenerator 54.

Indications are provided to a signaling message detector and analyzer68. The detector and analyzer operate to detect the contents of thesignaling message and analyze the detected message to ascertain thenumber of hashes, or page indications, per access terminal indicated inthe message. Indications are provided, here by way of the line 72, to ahash generator 74. The hash generator is also provided with values ofthe input number, here indicated to be provided by way of the line 76,known to both the access network and access terminal. The time factor,known to both the access network and access terminal is also provided tothe generator 74, here represented by way of line 77. The hash generator74 operates in manners analogous to operation of the hash generator 38of the access network to perform hash functions upon the input number.And, the input number provided to the hash generator 74 corresponds tothe input number provided to the hash generator 38 on the line 42. Thenumber of hash values generated by the hash generator 74 corresponds tothe number identified by the detector and analyzer 68. Hash valuescreated by the hash generator 74 are provided to a QPCH (Quick PagingChannel), or other, page message detector 82. The hash values created bythe hash generator 74 identify to the page message detector 82 which ofthe page indication locations that should be monitored to determinewhether a page is broadcast to the access terminal. The messagebroadcast by the access network and detected and operated upon by theaccess terminal is an atomic message. That is to say, all of the bitsare received in a single message. Responsive to detections made by thedetector, an indication is provided to an access terminal (AT) statecontroller 84 to control the state into which the access terminal isplaced. And, when the QPCH message indicates that the access terminal ispaged, the access terminal begins to monitor a second page channel, forbroadcast of a second page message thereon. The receive part of theaccess terminal also monitors the second page channel. The pageindications in the message generated by the message generator 54 aretherefore sent pursuant to, i.e., in furtherance of the sending of thesecond page message on the second page channel.

In the event that the first quick page indication slot monitored by themessage detector indicates no page message broadcast to the accessterminal, the state controller places the access terminal into a sleepmode. If a first of the quick page indication slots monitored by thedetector indicates a page to have been broadcast, but a second of thequick page indication slots monitored by the detector indicates no page,the state controller also causes the access terminal to enter into alow-power, sleep mode. Additional page indications, if more than two,are analogously monitored. The occurrence of a false wakeup is reducedas one or more additional quick page indications are monitored toprovide further indication of whether a page has been sent to the accessterminal.

FIG. 2 illustrates a graphical representation, shown generally at 102,that shows the relationship between the occurrence of false wakeup andthe number of pages in the communication system 10 shown in FIG. 1,pursuant to exemplary operation. Plots 104 illustrate the generalproportional relationship between the number of pages to accessterminals in a multi-user communication scheme and the occurrence offalse wakeup, represented in terms of probability. Four plots, plots104-1, 104-2, 104-3, and 104-4, are shown. The plot 104-1 isrepresentative of the relationship when a single page indication isprovided to a particular access terminal in a page message to alert theaccess terminal of the page. A single hash value is generated, and thepage indication is populated in a single page indication locationdetermined by the single hash value. The plot 104-2 is representative oftwo page indication bits provided in the page message to alert aparticular access terminal of the page. Two hash values are generated,and the page indication locations in which the page indications arepositioned are determined by the two hash values. The plot 104-3 isrepresentative of use of three page indications in a page message toalert a particular access terminal of the page. Three hash values aregenerated and their values are determinative of the positioning of thethree page indication locations in which the page indications arepopulated. And, the plot 104-4 is representative of the relationshipbetween false wakeup occurrences when four page indications are used ina page message to page the access terminal.

Review of the plots shows that the number of page indications in a pagemessage that provides the lowest false wakeup probability for a givennumber of pages in the communication system, i.e., network activity,varies with the number of pages. Pursuant to operation of an embodimentof the present invention, advantage is taken of this relationship in theselection of the number of page indications to use per access terminal.Such selection is made, e.g., by the determiner 32 shown in FIG. 1.Selection is made in such a way as to minimize the false wakeupprobability. For each number of pages, i.e., network activity, selectionis made of the number of page indications that are to be used to page,in the quick page message, an access terminal. Using, for instance,plots analogous to the plots 104 shown in FIG. 2, the lowest curve foreach of the number of pages, i.e., network activity, is selected.Analysis indicates that, when a number of pages is relatively small, thelowest probability of false wakeup occurs when greater number of pageindications per access terminal are utilized. Conversely, at highernumbers of pages, i.e., network activity, lesser numbers of pageindications provides the lowest false wakeup probabilities. Changeoveroccurs at various thresholds, indicated in the representation of FIG. 2when plots cross one another.

Once determination and selection is made at the access network,indication of the selection is provided to an access terminal. Thenumber of page indications, known at both the access network and at theaccess terminal, permits operation of the apparatus 24 and 26 incoordinated manner. In the exemplary implementation, the page indicationvalues populating a quick page message are all received in the samemessage. The access terminal need not wake up at different times forseparate bits as all of the bits of the message are received at once inthe same message. Furthermore, the same page indicator values are hashedinstead of, as previously utilized, making divisions into multiplephysical groups. And, the page indication locations defined by the hashvalues are further able to be generated in a manner such that the pageindication locations are dissimilar. Rotation of the input number usedin the generation of the hash values decorrelates the hash values, andthe introduction of time variance in the hash function also provides forhash value dissimilarity.

FIG. 3 illustrates an exemplary quick page message, shown generally at108. The message is generated, for instance, with respect to theconfiguration shown in FIG. 1, at the message generator 54. The quickpage message includes a plurality, here 33, page indication locations112, numbered as 1-33. Initially, each page indication location is setto logical “0” values. Page indications for four access terminals 12,identified as AT1, AT2, AT3, and AT4, are represented in the message108. A hash generator generates hash values of 8 and 6 for the accessterminal AT1. And, page indication locations 8 and 6 are populated withvalues to indicate whether the access terminal AT1 is paged. Here, thelogical values “1” are inserted into the page indication locations 8 and6 that identify that the AT1 is paged. Analogously, with respect to theaccess terminal AT2, the hash generator generates hash values of 7 and21, and page indications are inserted into page indication locations 7and 21 to identify that the access terminal AT2 is paged. Hash values 21and 13 generated with respect to the access terminal AT3 cause pageindication locations 21 and 13 to be populated with page indication bitsto identify, here, that the access terminal AT3 is paged. And, hashvalues generated with respect to the access terminal AT4 of 25 and 3cause the page indication locations 25 and 3 to be populated with pageindication bits, here again to identify that the access terminal AT4 ispaged. In this implementation, any of the page indication locations ofthe message 108 are available to be populated with page indication bitsassociated with any of the access terminals. And, as indicated at thepage indication location 21, a page indication location might include apage indication bit associated with more than one of the accessterminals. Ideally, the hash generator generates hash values that permiteven, viz. equal, distribution of page indication values across theentire message 108. Each hash for a particular access terminal hashesover the same page indication location in contrast to conventionalprocedures. And, through use of the time factor, the occurrence ofrepeated generation of hash values of similar values, and correspondingpopulation of the same page indication locations, for a particularaccess terminal, is unlikely.

FIG. 4 illustrates another message, here shown generally at 116 thatalso includes thirty-three page indication locations 112 that arepopulated with page indication values, here again to page accessterminals AT1, AT2, AT3, and AT4. Here, the message is divided into twogroups, a first group 118, and a second group 122. Initially, here also,each page indication location is set to logical “0” values. In thisimplementation, only a single page indication location per group isavailable for page indicator values associated with a particular accessterminal. That is to say, with respect to the access terminal AT1, asingle page indication location in the first group is available, and asingle page indication location in the second group is available. When ahash value generated by the hash value generator is of a value withinthe first group, another hash value must be of a value within the secondgroup. Ideally, the hash generator generates hash values that permiteven distribution of page indication values across each group of themessage. And, as shown in the representation of FIG. 4, a pageindication location is available to each of the access terminals in thefirst group and in the second group. The example shown in FIG. 4 is foran implementation in which two page indication bits are available withinthe page message per access terminal. If additional page indication bitsare available, the page message is divided into additional numbers ofgroups of substantially equal size, and the page indication locationsare correspondingly made available in each of the additional numbers ofgroups.

FIG. 5 illustrates a quick page message 126 and the manner by which ahash generator operates pursuant to another embodiment. Here, four pageindication locations are made available to the access terminal AT1 overthe thirty-three bits of the quick page message. And, again, each pageindication location is initially set to logical “0” values. When a hashvalue is selected and the page indication location 112 determinedtherefrom is used, that page indication location is no longer availableto that access terminal at which to populate the message with anotherpage indication value. That is to say, a hash value cannot be repeatedfor that access terminal. In the representation shown in FIG. 5, a firstpage indication value is populated in page indication location 10. Herealso, ideally, the hash generator generates hash values that permit evendistribution of page indications across all of the available pageindication locations. As noted below, when a page indication location isused, the location becomes no longer available. Page indication location10 is no longer available for the access terminal AT1. A next-generatedhash value is of 11 and a page indication bit is inserted into the pageindication location 11. Thereafter, neither page indication locations 10nor 11 are available. A subsequently-generated hash value of 20 causesthe page indication value to be inserted into page indication location20. And, thereafter, page indication locations 10, 11, and 20 are nolonger available. A fourth-generated hash value of 5 is generated, andthe page indication location 5 is populated with a page indicationvalue. In this implementation, use of a time factor is generally notrequired.

FIG. 6 shows a method flow diagram, shown generally at 132,representative of exemplary operation of an embodiment of the presentinvention for a communication system that selectably generates pagemessages on a first channel.

First, and as indicated by block 134, a signaling message is generatedthat indicates a selected number of hashes to page indications thatshall be generated within a page message sent upon the first channel.Then, and as indicated by the block 136, a page message is formed of thepage indications corresponding to the selected number of hashes.

As indicated by the block 138, the signaling message is sent upon thefirst channel. The signaling message is detected, indicated by the block142, at an access terminal together with the selected number of hashesto quick page indicator slots that are contained in the signalingmessage. And, as indicated by the block 144, the page message isdetected at the access terminal, and a determination is made whether thepage message includes the page indications corresponding to the selectednumber of hashes.

Thereby, through operation of an embodiment of the present invention, anaccess terminal is able better, and quickly, to determine whether a pageis broadcast thereto. If a quick page message, page indication locationto which the access terminal hashes fails to include an indication thatthe access terminal is being paged, the access terminal enters into areduced power state. The occurrence of false wakeup is less likely tooccur due to the multi-hashing to the multiple quick paging indicationslots.

Presently preferred embodiments of the invention and many of itsimprovements and advantages have been described with a degree ofparticularity. The description is of preferred examples of implementingthe invention, and the description of preferred examples is notnecessarily intended to limit the scope of the invention. The scope ofthe invention is defined by the following claims.

1. A method for generating hash values used pursuant to communication ofa paging message, said method comprising: generating a first hash valueat a hash generator using a first decorrelate (DECORR) value, whereinthe first DECORR value is a first multiple of an input number, whereinthe input number comprises at least a portion of a session seed known toboth an access network and an access terminal; generating a second hashvalue at the hash generator using a second DECORR value, wherein thesecond DECORR value is a second multiple of the input number; and usingthe first hash value and the second hash value to determine a first pageindication location and a second page indication location, respectively,for a page in the paging message.
 2. The method of claim 1 wherein theinput number comprises a group of significant bits of the session seed.3. The method of claim 1, further comprising: rotating the input numbera first number of bits after generating the first hash value.
 4. Themethod of claim 3 wherein the input number comprises a multi-bit binarynumber and wherein said rotating comprises multiplying the multi-bitbinary number.
 5. The method of claim 1 wherein the first hash value andthe second hash value are dissimilar.
 6. The method of claim 1 whereinsaid generating the first hash value and said generating the second hashvalue are performed using a common hash function.
 7. The method of claim1 wherein the paging message comprises a received paging messagereceived at an access terminal and wherein generating the first hashvalue, generating the second hash value, and said using are performed atthe access terminal.
 8. The method of claim 1 wherein the paging messagecomprises a send-paging message formed at a network entity and whereingenerating the first hash value, generating the second hash value, andsaid using are performed at the network entity.
 9. The method of claim 1further comprising generating a signaling message that includesindication of configuration of the paging message.
 10. The method ofclaim 1 further comprising configuring the paging message to be anatomic message.
 11. The method of claim 1 further comprising: generatinga third hash value using a third DECORR value, wherein the third DECORRvalue is a third multiple of the input number; and using the third hashvalue to determine a third page indication location for the page in thepaging message.
 12. A method for generating hash values used pursuant tocommunication of a paging message, said method comprising: generating afirst hash value at a hash generator using a first decorrelate (DECORR)value, wherein the first DECORR value is a first multiple of an inputnumber, wherein the input number comprises at least a portion of asession seed known to both an access network and an access terminal;using the first hash value to determine a first page indication locationfor a page in the paging message, the first page indication locationbeing in a first group of bits of the paging message; generating asecond hash value at the hash generator using a second DECORR value,wherein the second DECORR value is a second multiple of the inputnumber; using the second hash value to determine a second pageindication location for the page in the paging message, the second pageindication location being in a second group of bits of the pagingmessage, the second group of bits being different from the first groupof bits; generating a third hash value at the hash generator using athird DECORR value, wherein the third DECORR value is a third multipleof the input number; using the third hash value to determine a thirdpage indication location for the page in the paging message, the thirdpage indication location being in a third group of bits of the pagingmessage, the third group of bits being different from the first group ofbits and different from the second group of bits; generating a fourthhash value at the hash generator using a fourth DECORR value, whereinthe fourth DECORR value is a fourth multiple of the input number; andusing the fourth hash value to determine a fourth page indicationlocation for the page in the paging message, the fourth page indicationlocation being in a fourth group of bits of the paging message, thefourth group of bits being different from the first group of bits,different from the second group of bits, and different from the thirdgroup of bits.
 13. An apparatus in an access network, said apparatuscomprising: processing circuitry configured to execute algorithms whichwhen executed cause the processing circuitry to implement: a hashgenerator configured to generate a first hash value using a firstdecorrelate (DECORR) value, wherein the first DECORR value is a firstmultiple of an input number and to generate a second hash value using asecond DECORR value, wherein the second DECORR value is a secondmultiple of the input number, wherein the input number comprises atleast a portion of a session seed known to both the access network andan access terminal; and a paging message element that receives the firsthash value and the second hash value, said paging message elementconfigured to utilize the first hash value to determine a first pageindication location for a page in a paging message, and configured toutilize the second hash value to determine a second page indicationlocation for the page in the paging message.
 14. The apparatus of claim13 wherein the input number comprises a group of bits of the sessionseed.
 15. The apparatus of claim 13 wherein the input number comprises amulti-bit binary number.
 16. The apparatus of claim 13 wherein saidpaging message element comprises a network-positioned element.
 17. Theapparatus of claim 13 wherein said paging message element comprises anaccess-terminal positioned element.
 18. The apparatus of claim 13further comprising a signaling message generator configured to generatea signaling message that includes indication of configuration of thepaging message.